image/decoders/nsGIFDecoder2.h
author Gregory Szorc <gps@mozilla.com>
Wed, 28 Jan 2015 13:37:00 -0800
branch14_0_Beta_Hedge
changeset 149461 5b81998bb7ab5aade597584417ea90b0995c586e
parent 87475 9cf740464cd01a801e50b1e22f1156756765f2bf
child 98529 f4157e8c410708d76703f19e4dfb61859bfe32d8
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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Chris Saari <saari@netscape.com>
 *   Bobby Holley <bobbyholley@gmail.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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#ifndef _nsGIFDecoder2_h
#define _nsGIFDecoder2_h

#include "nsCOMPtr.h"
#include "Decoder.h"
#include "imgIDecoderObserver.h"

#include "GIF2.h"

namespace mozilla {
namespace image {
class RasterImage;

//////////////////////////////////////////////////////////////////////
// nsGIFDecoder2 Definition

class nsGIFDecoder2 : public Decoder
{
public:

  nsGIFDecoder2(RasterImage &aImage, imgIDecoderObserver* aObserver);
  ~nsGIFDecoder2();

  virtual void WriteInternal(const char* aBuffer, PRUint32 aCount);
  virtual void FinishInternal();
  virtual Telemetry::ID SpeedHistogram();

private:
  /* These functions will be called when the decoder has a decoded row,
   * frame size information, etc. */

  void      BeginGIF();
  nsresult  BeginImageFrame(PRUint16 aDepth);
  void      EndImageFrame();
  void      FlushImageData();
  void      FlushImageData(PRUint32 fromRow, PRUint32 rows);

  nsresult  GifWrite(const PRUint8 * buf, PRUint32 numbytes);
  PRUint32  OutputRow();
  bool      DoLzw(const PRUint8 *q);

  inline int ClearCode() const { return 1 << mGIFStruct.datasize; }

  PRInt32 mCurrentRow;
  PRInt32 mLastFlushedRow;

  PRUint8 *mImageData;       // Pointer to image data in either Cairo or 8bit format
  PRUint32 *mColormap;       // Current colormap to be used in Cairo format
  PRUint32 mColormapSize;
  PRUint32 mOldColor;        // The old value of the transparent pixel

  // The frame number of the currently-decoding frame when we're in the middle
  // of decoding it, and -1 otherwise.
  PRInt32 mCurrentFrame;

  PRUint8 mCurrentPass;
  PRUint8 mLastFlushedPass;
  PRUint8 mColorMask;        // Apply this to the pixel to keep within colormap
  bool mGIFOpen;
  bool mSawTransparency;

  gif_struct mGIFStruct;
};

} // namespace image
} // namespace mozilla

#endif